As reflector 10 of U.S. Pat. No. 3,971,023 is assembled as shown in FIG. 1, each petal 20 shown in FIGS. 2 and 3 tends to twist about its longitudinal axis, causing detectable surface irregularities at or near the center of the fully assembled reflector, in turn causing degradation of the antenna gain characteristic. Such irregularities can be overcome by adding support truss behind the assembled petals. However, the present invention overcomes the tendency of each petal to twist by providing a petal overlap which gradually increases from outer rim to center of the reflector. Heretofore, nominal rms surface deviation was achieved by providing many precisely sized and positioned holes in a large or full overlap region of adjacent petals.
As also shown in FIG. 1, U.S. Pat. Nos. 3,971,023 and 3,832,717, describe reflectors having a rigid, segmented exterior rim 12 formed to receive the outer edges of the petals, provide mechanical support for mounting and positioning the antenna, and maintain mechanical integrity over a wide range of environmental conditions. The rim segments 14 are extruded channel stock coupled to one another by angular corner brackets 16. Such rim structure is tedious to manufacture and cumbersome to assemble. The present invention provides a rim structure constructed of preformed tubular segments. Such tubular segments require no comer brackets and provide greater strength when assembled and are easier to manufacture and assemble than prior art rim assemblies.